Some mobile terminals are capable of remotely operating a videocassette recorder at home to perform video recording. Even in a case of a failure to reserve recording for television programs at home, such a mobile terminal enables reserving away from home. Further, some mobile terminals are capable of remotely operating an air conditioner at home to turn on the power away from home. Such a mobile terminal enables making the room temperature comfortable when the user comes home back, which is very convenient.
Meanwhile, the Internet is becoming widely used. In addition, IP (Internet Protocol) is expected to be upgraded to version 6. Against a background of these circumstances, a large number of electronic apparatuses at home are expected to be connected to the Internet.
However, an information processing system in the above-mentioned conventional technology has direct access to electronic apparatuses at home from external apparatuses existing away from home using the Internet, for example. Therefore, the system has security problems. That is to say, unexpected external apparatuses and those of malicious users may set for operation and acquire status information of electronic apparatuses at home.